I find it somewhat ironic that only a few of the classes who can use Daggers actually use them for stabbing things. Anyway! There are quite a few interesting looking daggers, some One-Hand, some Main Hand.

And before you ask - Morgion is wearing a plain white dress because I didn't want the small Dagger blades lost against her normal dark leg armor. So it's for visibility's sake.

This quietly understated dagger has some nice detailing on it, and isn't outrageously huge. Purple blade, as is Phantom Dagger, another BoE green. The orange-bladed version pictured is Shattering Dagger, a Main Hand BoE.

Purple crystal and massive (for a Dagger), this Main Hand weapon also has an ice-blue One-Hand variant, Illidari-Bane Dagger. Sadly, these Daggers are quest rewards from the same quest, so you can only ever get one or the other. (The purple model is also available as a sword.)

29% drop rate. This unusual forked Dagger shares a model only with...itself. Or rather, the Heroic version of itself, which drops on - obviously - Heroic mode, at a 20% drop rate. The Heroic version is blue instead of yellow.

(Yellow blade) This can be found on the AH every now and then, and usually for reasonable prices. It shares a model with a black-bladed recolor, Unsharpened Ice Razor, which is random Bind-on-Pickup trash drop out of the ICC 5-man Heroics.

A red-hot poker! Very cool and full of flavor. 46% drop rate, first boss in SM: Graveyard, so very easily farmed. Has a twin, Flarethorn, which drops from Blackrock Depths at a 24% drop rate. (Just farm it from Scarlet Monastery, seriously.)

This mean-looking military blade (Red spikes in picture) is purchasable from your faction's respective Tol Barad quartermasters, requiring Revered reputation and costing 85 Tol Barad Commendations. Shares a model with Scaleslicer (Green spikes, Bind on Equip), though it will be hard to find.

Rough-edged and looks like it was made from flint or obsidian. Main Hand, 21% drop rate on Normal, 22% on Heroic. A version with blue/purple runes, Runesong Dagger, can be obtained from Shattered Halls (Normal and Heroic, 19% drop rate / 18% drop rate). It is also Main Hand.

This alien-looking Dagger is very unusual and distinct. One-Hand, 19% drop rate. Shares a model with a drop from Ahn'Qiraj, and with Vileblade of the Betrayer (One-Hand, Heroic Arcatraz, 16% drop rate).

Enormous Dagger that is as large as some swords. 17% drop rate. Shares a model with an Off-Hand variant, confusingly named the same thing, Twinblade of the Hakkari, which rops off the same boss at a 17% drop rate.

Fantastic list! Some of these I've saved over the years (even long ago, pre-transmog, cos BC gear was so interesting!), but others are true surprises, even after reading other transmog lists. Good job!